This invention relates to a cartridge based data storage system in which a flexible magnetic disk is disposed within a cartridge shell. More particularly, the invention relates to a cartridge having a shutter, wherein the shutter is adapted to open during insertion of the cartridge into a disk drive.
Microprocessors and supporting computer technologies are rapidly increasing in speed and computing power while decreasing in cost and size. These factors have led to the broad application of microprocessors to an array of electronic products, such as hand-held computers, digital cameras, cellular phones and the like. All of these devices have, in effect, become computers with particular application-specific attributes. For this new breed of computer products, enormous flexibility is gained by the ability to exchange data files and store computer software.
A variety of proprietary storage devices have been used in computer products. For example, hand-held computers have used integrated circuit memory cards ("memory cards") as the primary information storage media. Memory cards include memory storage elements, such as static random access memory (SRAM), or programmable and erasable non-volatile memory, such as "flash" memory. Memory cards each are typically the size of a conventional credit card and are used in portable computers in place of hard disk drives and floppy disk drives. Furthermore, memory cards enhance the significant advantages of the size, weight, and battery lifetime attributes of the portable computer and increase portability of the storage media. However, because of the limited memory density attainable in each memory card and the high cost of the specialized memory chips, using memory cards in hand-held computers imposes limitations not encountered in less portable computers, which typically use more power-consuming and heavier hard and floppy disk drives as their primary storage media.
Typical removable disk cartridges have a flexible magnetic disk disposed within a hard outer shell. A movable shutter is connected to the shell and selectively opens to expose the flexible magnetic disk. Such a cartridge is disclosed in U.S. Pat. No. Re, 32,876 (Wakabayashi et al.). The Wakabayashi patent is directed to a disk cassette that contains a flexible magnetic disk for storing information. The disk cassette comprises a flexible disk attached to a hub. The disk and hub assembly are sandwiched between an upper cover and a lower cover. The Wakabayashi shutter rotates on the interior of the cartridge and comprises a metal sheet that slides over a disk access opening to cover a head access opening.
A shutter and corresponding shutter opening mechanism are described in co-pending U.S. patent application Ser. No. 08/968,225, which is assigned to the same assignee as the present invention. Therein, a shutter mechanism is described that has radially extending tab that mates with a rotary shutter opening lever. As a cartridge is inserted into a drive, a hook-like shutter lever end engages the shutter tab and rotates the shutter open.
Prior art shutter opening mechanisms require levers and other complicated mechanisms to open a cartridge shutter. The complicated mechanism require several moving parts that could fail to operate consistently and thereby degrade the overall reliability and performance of the storage system. Accordingly, there is a need for a cartridge having an improved shutter opening mechanism.